Spring Framework 2.0 New Persistence Features. Thomas Risberg

Transcription

1 Spring Framework 2.0 New Persistence Features Thomas Risberg

2 Introduction Thomas Risberg Independent Consultant, springdeveloper.com Committer on the Spring Framework project since 2003 Supporting the JDBC and Data Access code Co-author of Professional Java Development with the Spring Framework from Wrox

3 In this presentation: Spring Overview What is new in Spring 2.0? Java Persistence API JSR 220 Spring s JDBC Abstraction Layer The Spring Framework Project

4 What is Spring? Spring is a Lightweight Application Framework covering all tiers of your typical business application Leverages services from underlying runtime environment (e.g. J2EE Services) Provides AOP services for security, transactions, management and remoting Integrates with other commonly used frameworks and libraries Greatly simplifies development effort Promotes modular, reusable coding practices

5 Features of Spring Spring Container Bean Factory Application Context Spring Web MVC DAO AspectJ AOP Web Flow ORM Transactions Management JMS JDBC Security Remoting

6 The Spring Triangle Dependency Spring Container Service Bean Factory Application Context Spring Web MVC DAO AspectJ AOP Abstractions Injection POJO AOP Web Flow ORM Transactions Management JMS JDBC Security Remoting

7 Why use Spring? Spring is not positioned to compete with J2EE or Java EE - it competes with in-house frameworks Many products today integrate with Spring WebLogic Server IntelliJ IDEA ServiceMix Active MQ Oracle TopLink Next 2-3 years? Java EE 5 with EJB 3 and JSF provides part of what Spring Offers today, but most Spring users will still need the extra features provided by Spring

8 Simpler, more extensible XML configuration What is new in Spring 2.0? Enhanced integration with AspectJ Portlet MVC Framework Improvements in Web MVC Framework Additional scoping options for beans Ability to define beans in scripting language like Groovy or JRuby Message-driven POJOs

9 What about persistence? Support for Java Persistence API (EJB 3 JSR 220) JDBC simplifications: SimpleJdbcTemplate provides support for generics, varargs and autoboxing NamedParameterJdbcTemplate replaces traditional parameter placeholder with explicit parameter name SqlCommand objects extends named parameter support for ease of use

10 Spring s Current Persistence Support JDBC Abstraction - provides resource management and exception translation Support for a growing number of O/R Mappers ibatis SQLMaps Hibernate 2 and 3 JDO including JDO 2 TopLink OJB DAO support, transaction management and exception translations for all data access choices

11 Java Persistence API JSR 220 Works with POJOs Standardizes: - ORM Metadata - API - Lifecycle / Callbacks - Query Language Improves testability and removes need for DTOs

12 Primary API Interfaces PersistenceContext Transaction-scoped / Extended EntityManager Resource-local / JTA Container- / / JNDI / emf.createentitymanager() EntityManagerFactory

13 entitymanager.gettransaction().begin(); List l = entitymanager.createquery( "select object(s) from ticket.domain.show s").getresultlist(); entitymanager.gettransaction().commit(); API usage varies List l = entitymanager.createquery( "select object(s) from ticket.domain.show s").getresultlist(); JTA and Resourcelocal

14 Spring will attempt to bridge these differences and provide a consistent style for programming in various environments. This also applies when using using other O/R Mapping solutions - the same programming style is used throughout.

15 JPA Support In org.springframework.orm.jpa package Support classes correspond with ones for other ORM implementations like Hibernate, TopLink and JDO JpaTemplate, JpaCallBack and JpaInterceptor provide integration with transaction management and uses thread bound EntityManager for the persistence context JpaDaoSupport is convenience class for DAO usage JpaTransactionManager handles resource local access and JtaTransactionManager handles JTA transactions LocalEntityManagerFactorybean provides resource local bootstrapping for Java SE while JndiObjectFactoryBean does the JNDI lookups in Java EE environments

16 Persistence Example Data Model

17 JPA Entity Mapping

18 Service/Manager Layer

19 Application Context

20 XML Configuration Simplification VS

21 Direct use of JPA API

22 Direct use of JPA API To get proper transaction management use JNDI lookup in a JTA environment and SharedEntityManagerAdapter for a Resource-local configuration No exception translation provided

23 Spring s JDBC Abstraction Layer New in 2.0: SimpleJdbcTemplate NamedParameterJdbcTemplate SqlCommand

24 SimpleJdbcTemplate Designed to take advantage of Java 5 features generics varargs autoboxing Wraps a regular JdbcTemplate and if you need additional methods use getjdbcoperations method to access it.

25 SimpleJdbcTemplate

26 SimpleJdbcTemplate

27 Named Parameters Compare this SQL statement: select id, price, brand from product where price <? and brand <>? with the following select id, price, brand from product where price < :maxprice and brand <> :unwantedbrand

28 NamedParameterJdbcTemplate Allows the use of named parameters in any SQL statement. Use a Map to pass in parameter values Map key matches value with parameter name If parameter value is a List then placeholders will be expanded to cover all list members - watch the size of the list! Wraps a regular JdbcTemplate and if you need additional methods use getjdbcoperations method to access it.

29 NamedParameterJdbcTemplate if value is a List we will expand placeholders

30 NamedParameterJdbcTemplate creates a Map containing name and value of all public getters

31 SqlNamedParameterHolder Common methods: Map getvalues() Map gettypes() void setvalues(map) void gettypes(map)

32 SqlCommand Alternativ to RdbmsOperation (SqlQuery, SqlUpdate...) No need to explicitly declare parameters - we declare the name in the SQL statement and can declare the Type in a SqlNamedParameterHolder Thread-safe, but lightweight and inexpensive to create whenever needed Various execute methods depending on requested return type: Object executescalar() Object executeobject(rowmapper) List executequery() int executeupdate()

33 SqlCommand

34 SqlCommand

35 Started February 2003 The Spring Framework Project Based on code from Rod Johnsons book J2EE Design and Development Website CVS repository is on SourceForge released March released May released Q Spring Experience conference Dec SpringOne conference June 2006

36 Development & Support Development 80% of core committers work for Interface21 Commercial Support Interface21 -- wrote the code BEA -- certified on WebLogic 9.0 SpikeSource -- Spike Servlet/J2EE Stack SourceLabs -- SASH 1.1(certified by Oracle)

37 Training & Documentation Training Interface21 Virtuas ArcMind Documentation / Books

38 Community Support Forum - forum.springframework.org User Groups Philadelphia, PA - Dallas, TX - Sydney, Australia Conferences

39 PSUG Philadelphia Spring Users Group Meeting -- Tuesday April 4, :00pm - 9:00pm Joint meeting with the Delaware Valley BEA Users Group Spring, BEA and Service-Oriented Architectures